Half to eichaed e



(No Model.)

L. 'COLBURN.

ELEGTRIG ARC LAMP.

Patented Apr. 21

Uwrrao STATES PATENT OFFICE.

LEDYARD COLBURN, OF BIRMINGHAM, CONNECTICUT, ASSIGNOR OF ONE- HALF TORICHARD R. COLBURN, OF SAME PLACE.

ELECTRIC-ARC LAMP.

SPECIFICATION forming part of Letters Patent No. 316,240, dated April21, 1885.

Application filed March 13, 1884.

1 and which said drawing constitutes part of this specification, andrepresents a sectional side view showing the two carbons of an arc lampwith the gas-jet and air-jet arranged independent of the carbons. Thisinvention relates to an improvement in electric-arc lamps, the object ofthe invention being to reduce the electric current with-' outdiminishing the brilliancy of the light; and my invention consists incombining with the carbons of an electricarc lamp ajet of air and gasimpinging directly upon the points of the carbons, so that the air andgas will mingle at those points and produce an intense heat upon thepoints, and whereby the elecz 5 trio current may be reduced to theextent that the carbons are heated by the gas, as more fully hereinafterdescribed.

A represents one carbon and B the other carbon of a common arc lamp, toeach of which 0 the lines are led to form the are between the points ofthe two carbons.

C is a contracting tube, terminating near the points of the carbon; D, alike tube, preferably arranged directly opposite the point of the tube(No model.)

C. To one of the tubessay C-gas is sup- 5 plied, and to the other tube,D, air is supplied, the quantity of air and gas being regulated by cocksE or otherwise.

When the circuit is closed and the are formed between the two burners,the gas is supplied 0 through the tube C, and instantly ignites. At thesame time air is introduced through the other tube, D, in sufficientquantity to mingle with the gas and produce perfect combustion.Therefore this combined gas and air produces 5 an intense heat directlyat the points of the carbons, and which, with a greatly-reduced electriccurrent, will heat the carbons to a point of brilliancy equal at leastto the most brilliant effect produced by the usual strong electriccurrent.

The air and gas may be supplied by any de vice which will deliver themunder the requisite pressure.-

Ido not claim, broadly, supplying mixed gas and air at the points of theelectrodes,,as such,

I am aware, is not new.

I claim In an electric-arc lamp, the combination of the two carbons A Bwith the tubes C D, ap- 6o plied to direct, respectively, a gas and anair jet between the points of the carbons, substantially as described.

LEDYARD COLBURN.

Witnesses:

J OHN E. EARLE, J 0s. 0. EARLE.

